os: make Stat work on FAT file system
os: make Stat work on FAT file system

It appears calling GetFileInformationByHandleEx with
FILE_ATTRIBUTE_TAG_INFO fails on FAT file system. FAT does not
support symlinks, so assume there are no symlnks when
GetFileInformationByHandleEx returns ERROR_INVALID_PARAMETER.

Fixes #29214

Change-Id: If2d9f3288bd99637681ab5fd4e4581c77b578a69
Reviewed-on: https://go-review.googlesource.com/c/154377
Run-TryBot: Alex Brainman <54ba58c8441b5eff861de6b4e5ee46baf086b142@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

golang/go,CAFxX/go,nawawi/go,CAFxX/go,josharian/go,akutz/go,CAFxX/go,cloudflare/go,josharian/go,cloudflare/go,cloudflare/go,golang/go,cloudflare/go,cloudflare/go,CAFxX/go,cloudflare/go,akutz/go,akutz/go,nawawi/go,josharian/go,CAFxX/go,nawawi/go,nawawi/go,nawawi/go,akutz/go,akutz/go,josharian/go,cloudflare/go,akutz/go,CAFxX/go,josharian/go,nawawi/go,nawawi/go,golang/go,CAFxX/go,golang/go,cloudflare/go,golang/go,nawawi/go,golang/go,josharian/go,josharian/go,golang/go,akutz/go,akutz/go,CAFxX/go,josharian/go,golang/go